Condensed Consolidating Information - Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Condensed Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities	$ 157,972	$ 309,212	$ 446,871	$ 543,919
Net cash used in investing activities	(34,480)	(22,015)	(59,134)	(53,703)
Net cash provided by (used in) financing activities	(47,777)	(28,778)	(62,103)	(432,178)
Increase in cash and equivalents	75,715	258,419	325,634	58,038
Cash and equivalents at beginning of period	976,951	160,982	727,032	361,363
Cash and equivalents at end of period	1,052,666	419,401	1,052,666	419,401
Reportable legal entity | Parent
Condensed Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			183,719	212,624
Net cash used in investing activities			(19,031)	(31,419)
Net cash provided by (used in) financing activities			145,453	(94,522)
Increase in cash and equivalents			310,141	86,683
Cash and equivalents at beginning of period			636,877	265,313
Cash and equivalents at end of period	947,018	351,996	947,018	351,996
Reportable legal entity | Guarantors
Condensed Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			264,839	322,486
Net cash used in investing activities			(35,026)	(18,495)
Net cash provided by (used in) financing activities			(222,896)	(330,095)
Increase in cash and equivalents			6,917	(26,104)
Cash and equivalents at beginning of period			81,976	81,690
Cash and equivalents at end of period	88,893	55,586	88,893	55,586
Reportable legal entity | Combined Non-Guarantors
Condensed Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			(2,066)	246
Net cash used in investing activities			(4,746)	(13,260)
Net cash provided by (used in) financing activities			15,388	10,473
Increase in cash and equivalents			8,576	(2,541)
Cash and equivalents at beginning of period			8,179	14,360
Cash and equivalents at end of period	$ 16,755	$ 11,819	16,755	11,819
Consolidating Adjustments
Condensed Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			379	8,563
Net cash used in investing activities			(331)	9,471
Net cash provided by (used in) financing activities			$ (48)	$ (18,034)